The present invention relates to a method and apparatus for cutting a glass blank according to a particular contour. The invention is particularly useful for cutting glass blanks in making windshields for motor vehicles, and is therefore described below with respect to this application.
The manufacture of windshields for motor vehicles involves first scoring the contour of the windshield on a glass blank, severing the scored contour from the glass blank, and grinding the edges of the severed blank. The glass blank is then bent into the required shape and is subjected to a thermal treatment. When a laminated windshield is produced, two such glass blanks are joined together with a transparent adhesive.
At the present time, the scoring, severing and grinding operations are usually performed manually with the aid of patterns traced by a tracing wheel. Recently, computerized numerical control (CNC) scoring machines have been developed for controlling the scoring operation by digital data manually prepared by the use of a digitizer table. However, even with the use of such CNC scoring machines, the grinding is still performed by the use of a tracing wheel.
An object of the present invention is to provide a novel method and apparatus for automatically cutting a glass blank according to a particular contour, which method and apparatus are particularly useful in making windshields for automotive vehicles. Other objects of the invention are to provide a novel scoring machine, a novel breaking machine, and a novel grinding machine, all computer-controlled, for use in cutting glass blanks.